<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <script>
    /* 
    js引擎在执行我们的代码前, 它会先执行内置代码, 创建一系列的函数对象
    Function / Object / String / Number / Boolean / Date /...
    */
    function Fn () {}
    const fn1 = new Fn()
    const fn2 = new Fn()
    const o1 = new Object()
    const o2 = {}


    console.log(Fn.prototype)

    console.log(Function.prototype.__proto__===Object.prototype)
    console.log(Function.prototype, {})

    /* 
    内部执行: Function.prototype.__proto__ = Object.prototype
    */

    console.log(Fn instanceof Object)
    console.log(Fn instanceof Function)
    console.log(Object instanceof Function)
    console.log(Object instanceof Object)
    console.log(Function instanceof Object)
    console.log(Function instanceof Function)
    console.log(fn1 instanceof Function)
    console.log(Object instanceof Fn)
  </script>
</body>
</html>